with "malcolm in the middle" star frankie muniz opening up about his medical scare. A ministroke. And this is not his first one. 9:23, I win. Reporter: Former "malcolm in the middle" star, frankie muniz, revealing his recently suffered a second ministroke. He tweeted monday, almost a year to the day, I experienced another ministroke. Hopefully that will be the last. Last december, muniz told "gma" about the stroke. I couldn't say words. Reporter: A ministroke occurs when blood flow to the brain stops temporarily. Rare for a man who is not only healthy but also under 30. Strokes in young people are not very common. But they do occur. Often, you don't find out the cause. But it may be from a hole in the heart, a torn artery. Reporter: The 27-year-old said last year, he was proud of his healthy lifestyle. I'm literally to this day, never had a sip of alcohol in my life. I never had any drugs. I never even smoked a cigarette. Reporter: Medical experts say you should know the signs of a stroke and remember the acronym f.A.S.T. "F" is for face. "A" for arm. "S" is for speech. And "t" is for time. Reporter: Muniz has traded the small screen for the stage. He lives in phoenix and is the drummer for the band kings foil. When you're young, you don't think a stroke is something that can happen to you. This just shows you really do need to know the signs. So glad he's okay. And so much to look forward to. Frankie's engaged to be married. Wish him nothing but the best.

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